U.S. patent application number 10/518281 was filed with the patent office on 2005-10-06 for ball bearing.
Invention is credited to Kawaguchi, Toshihiro, Nakashita, Tomonori, Ogino, Kiyoshi, Tadumi, Hajime, Ueda, Hideo, Yokota, Kunihiko.
Application Number | 20050220383 10/518281 |
Document ID | / |
Family ID | 32684184 |
Filed Date | 2005-10-06 |
United States Patent
Application |
20050220383 |
Kind Code |
A1 |
Yokota, Kunihiko ; et
al. |
October 6, 2005 |
Ball bearing
Abstract
First and second annular clearances are formed between an outer
peripheral surface of an annular portion of a cage and an inner
peripheral surface of an annular piece of a first outer ring
member, and between an inner peripheral surface of a baffle piece
and an outer peripheral surface of a shoulder portion of a first
inner ring member, respectively, and these radial widths are set to
be larger than 0 and 0.15 times or less of a diameter of a ball,
respectively.
Inventors: |
Yokota, Kunihiko; (Osaka,
JP) ; Nakashita, Tomonori; (Osaka, JP) ;
Tadumi, Hajime; (Osaka, JP) ; Ogino, Kiyoshi;
(Osaka, JP) ; Ueda, Hideo; (Osaka, JP) ;
Kawaguchi, Toshihiro; (Osaka, JP) |
Correspondence
Address: |
JORDAN AND HAMBURG LLP
122 EAST 42ND STREET
SUITE 4000
NEW YORK
NY
10168
US
|
Family ID: |
32684184 |
Appl. No.: |
10/518281 |
Filed: |
December 15, 2004 |
PCT Filed: |
December 17, 2003 |
PCT NO: |
PCT/JP03/16173 |
Current U.S.
Class: |
384/523 |
Current CPC
Class: |
F16C 19/548 20130101;
F16C 33/6674 20130101; F16C 33/405 20130101; F16C 19/182 20130101;
F16C 2361/61 20130101; F16H 57/021 20130101; F16C 2240/46 20130101;
F16C 2240/80 20130101; F16H 2048/423 20130101; F16C 33/414
20130101; F16C 33/7893 20130101; F16H 57/037 20130101 |
Class at
Publication: |
384/523 |
International
Class: |
F16C 033/38 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 19, 2002 |
JP |
2002-367722 |
Feb 3, 2003 |
JP |
200325547 |
Claims
What is claimed is:
1. A ball bearing, comprising: an inner ring member having double
raceway surfaces; an outer ring member which is concentrically
arranged with said inner ring member and has double raceway
surfaces corresponding to each raceway surface of said inner ring
member; double row balls which are arranged between the raceway
surfaces of each row of said inner ring member and said outer ring
member; and cages for holding said balls in each row, wherein one
cage among these cages comprises a pocket portion for housing said
balls, and an annular portion integrally formed with this pocket
portion, and wherein said annular portion of said one cage is
arranged between a shoulder portion of said inner ring member and a
shoulder portion of said outer ring member via a clearance having a
radial fine dimension.
2. A ball bearing, comprising: an inner ring member having raceway
surfaces with different diameters on a major diameter side and a
minor diameter side; an outer ring member which is concentrically
arranges with said inner ring member and has raceway surfaces with
different diameters on the major diameter side and the minor
diameter side corresponding to each raceway surface of said inner
ring member; double row balls which are arranged between respective
raceway surfaces of said inner ring member and said outer ring
member; and cages on the major diameter side and the minor diameter
side for holding said balls in each row, wherein the cage on the
minor diameter side among said cages comprises a pocket portion for
housing said balls, and an annular portion integrally formed with
this pocket portion, and wherein said annular portion of said cage
on the minor diameter side is arranged between a shoulder portion
of said inner ring member and a shoulder portion of said outer ring
member via a clearance having a radial fine dimension.
3. A ball bearing used in a part where a lubricant passes through
an annular space between an inner ring member and an outer ring
member, comprising: an inner ring member having double raceway
surfaces; an outer ring member which is concentrically arranged
with said inner ring member and has double raceway surfaces
corresponding to each raceway surface of said inner ring member;
double row balls which are arranged between the raceway surfaces of
each row of said inner ring member and said outer ring member; and
cages for holding said balls in each row, wherein one cage among
said cages comprises a pocket portion for housing said balls, and
an annular portion integrally formed with this pocket portion, and
wherein said annular portion of said one cage is arranged between a
shoulder portion of said inner ring member and a shoulder portion
of said outer ring member via a clearance having a radial fine
dimension.
4. A ball bearing used in a part where a lubricant passes through
an annular space between an inner ring member and an outer ring
member, comprising: an inner ring member having raceway surfaces
with different diameters on a major diameter side and a minor
diameter side; an outer ring member which is concentrically
arranges with said inner ring member and has raceway surfaces with
different diameters on the major diameter side and the minor
diameter side corresponding to each raceway surface of said inner
ring member; double row balls which are arranged between respective
raceway surfaces of said inner ring member and said outer ring
member; and cages on the major diameter side and the minor diameter
side for holding the balls in each row, wherein the cage on the
minor diameter side among said cages comprises a pocket portion for
housing said balls, and an annular portion integrally formed with
this pocket portion, wherein said annular portion of said cage on
the minor diameter side is arranged between a shoulder portion of
said inner ring member and a shoulder portion of said outer ring
member via a clearance having a radial fine dimension.
5. A ball bearing according to claim 4, wherein an axial end face
on a side of the raceway surface with major diameter of said outer
ring member is axially closely positioned to the side of the
raceway surface with minor diameter of said inner ring member
compared with an axial end face of a side of the raceway surface
with major diameter of said inner ring member.
6. A ball bearing according to claim 5, wherein a line of action of
a bearing portion on the side of the raceway surface with major
diameter is inclined towards a bearing portion on a side of the
raceway surface with minor diameter.
7. A ball bearing used in a part where a lubricant passes through
an annular space between an inner ring member and an outer ring
member, comprising: an inner ring member having a single raceway
surface; an outer ring member which is concentrically arranged with
said inner ring member and has a single raceway surface
corresponding to said raceway surface of said inner ring member; a
plurality of balls arranged between raceway surfaces of said inner
ring member and said outer ring member; and a cage for holding
these balls, wherein said cage comprises a pocket portion for
housing said balls, and an annular portion integrally formed with
this pocket portion, and wherein said annular portion of said cage
is arranged between a shoulder portion of said inner ring member
and a shoulder portion of said outer ring member via a clearance
having a radial fine dimension.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a ball bearing used for a
differential mechanism or the like which is mounted on, for example
a vehicle.
DESCRIPTION OF THE PRIOR ART
[0002] A pinion shaft of a differential mechanism mounted on a
vehicle is rotatably supported by means of a tapered roller bearing
at its both sides in an axial direction. If the pinion shaft is
supported by means of the tapered roller bearing, running torque is
increased, so that efficiency of the differential mechanism may be
deteriorated. For this reason, a technology for supporting the
pinion shaft by means of a double row ball bearing has been
proposed (refer to, for example Japanese Patent Application
Publication No. 2002-117091).
[0003] FIG. 8 is a cross sectional view of a differential mechanism
100 which employs a double row ball bearing for supporting a pinion
shaft. The pinion shaft 102 which is rotatably supported about a
shaft center by a pair of ball bearings 103 and 104 is housed
within a differential retaining shield 101 of the differential
mechanism 100. The ball bearings 103 and 104 have a configuration
in which PCDs (Pitch Circle Diameter) of balls of each row, inner
and outer ring raceway diameters thereof are different, and are
called a tandem type double row ball bearing.
[0004] Incidentally, when the pinion shaft begins to rotate, oil in
the differential retaining shield 101 reaches an oil outlet port
107 from an oil inlet port 106 of an oil circuit 105, is led so as
to be supplied to an upper part of the ball bearings 103 and 104,
and circulates within the differential retaining shield 2 so as to
lubricate the ball bearings 103 and 104.
[0005] As described above, when the oil is introduced into the ball
bearings 103 and 104, since the ball bearings 103 and 104 are the
tandem type ball bearings and the pinion shaft rotates about the
shaft center, there is high possibility that a large amount of oil
among the oil supplied between bearing rings in the ball bearings
103 and 104 will be supplied into the ball bearings 103 and
104.
SUMMARY OF THE INVENTION
[0006] A ball bearing of the present invention comprises: an inner
ring member having double raceway surfaces; an outer ring member
which is concentrically arranged with said inner ring member and
has double raceway surfaces corresponding to each raceway surface
of said inner ring member; double row balls which are arranged
between the raceway surfaces of each row of said inner ring member
and said outer ring member; and cages for holding the balls in each
row in equally distributed positions in a circumferential
direction, wherein one cage among these cages comprises a pocket
portion for housing said balls, and an annular portion integrally
formed with this pocket portion, and wherein the annular portion of
said one cage is arranged between a shoulder portion of said inner
ring member and a shoulder portion of said outer ring member via a
clearance having a radial fine dimension.
[0007] The annular portion of the cage is arranged between the
shoulder portions of the inner and outer ring members via the
clearance having the radial fine dimension as above configuration,
so that a lubricant is supplied between the outer ring member and
the inner ring member as much amount as needed, thereby making it
possible to certainly lubricate the inside of the ball bearing in a
state of suppressing an increase in torque.
[0008] Moreover, a ball bearing of the present invention comprises:
an inner ring member having raceway surfaces with different
diameters on a major diameter side and a minor diameter side; an
outer ring member which is concentrically arranges with this inner
ring member and has raceway surfaces with different diameters on
the major diameter side and the minor diameter side corresponding
to each raceway surface of said inner ring member; double row balls
which are arranged between respective raceway surfaces of said
inner ring member and said outer ring member; and cages on the
major diameter side and the minor diameter side for holding the
balls in each row in equally distributed positions in the
circumferential direction, wherein the cage on the minor diameter
side among said cages comprises a pocket portion for housing said
balls, and an annular portion integrally formed with this pocket
portion, and wherein said annular portion of said cage on the minor
diameter side is arranged between a shoulder portion of said inner
ring member and a shoulder portion of said outer ring member via a
clearance having a radial fine dimension.
[0009] In the so-called tandem type double row ball bearing
provided with the raceway surfaces with the different diameters in
the inner and outer ring members as above configuration, it has
been difficult to restrict the amount of lubricant in particular,
but according to an easy configuration of arranging the annular
portion of the cage between the shoulder portions of the inner and
outer ring members via the clearance having the radial fine
dimension, the lubricant can be supplied between the outer ring
member and the inner ring member as much amount as needed, thereby
making it possible to certainly lubricate the inside of the ball
bearing in a state of suppressing an increase in torque.
[0010] Moreover, a ball bearing of the present invention is a ball
bearing used in a part where a lubricant passes through an annular
space between an inner ring member and an outer ring member, it
comprises: an inner ring member having double raceway surfaces; an
outer ring member which is concentrically arranged with this inner
ring member and has double raceway surfaces corresponding to each
raceway surface of said inner ring member; double row balls which
are arranged between the raceway surfaces of each row of said inner
ring member and said outer ring member; and cages for holding the
balls in each row in equally distributed positions in the
circumferential direction, wherein one cage among said cages
comprises a pocket portion for housing said balls, and an annular
portion integrally formed with this pocket portion, and wherein
said annular portion of the one cage is arranged between a shoulder
portion of said inner ring member and a shoulder portion of said
outer ring member via a clearance having a radial fine
dimension.
[0011] In the ball bearing used in a part where the lubricant
passes through an annular space between said inside and outside
rings as described above, it has been difficult to restrict the
amount of lubricant in particular, but according to an easy
configuration of arranging the annular portion of the cage between
the shoulder portions of the inner and outer ring members via the
clearance having the radial fine dimension, the lubricant can be
supplied between the outer ring member and the inner ring member as
much amount as needed, thereby making it possible to certainly
lubricate the inside of the ball bearing in a state of suppressing
an increase in torque.
[0012] Moreover, a ball bearing of the present invention is a ball
bearing used in a part where a lubricant passes through an annular
space between an inner ring member and an outer ring member, it
comprises: an inner ring member having raceway surfaces with
different diameters on a major diameter side and a minor diameter
side; an outer ring member which is concentrically arranged with
this inner ring member and has raceway surfaces with different
diameters on the major diameter side and the minor diameter side
corresponding to each raceway surface of said inner ring member;
double row balls which are arranged between respective raceway
surfaces of said inner ring member and said outer ring member; and
cages on the major diameter side and the minor diameter side for
holding the balls in each row in equally distributed positions in
the circumferential direction, wherein the cage on the minor
diameter side among said cages comprises a pocket portion for
housing said balls, and an annular portion integrally formed with
this pocket portion, and wherein said annular portion of said cage
on the minor diameter side is arranged between a shoulder portion
of said inner ring member and a shoulder portion of said outer ring
member via a clearance having a radial fine dimension.
[0013] In the tandem type double row ball bearing with different
raceway diameters in particular, in a state where, for example the
inner ring member is rotating about a shaft center, the lubricant
supplied to the annular space between the inner and outer ring
members flows out of the annular space at high speed compared with
that of a double row ball bearing with the same raceway
diameter.
[0014] However, in the ball bearing of the present invention, the
amount of lubricant supplied to the annular space is restricted, so
that a speed of the lubricant flowing within the annular space is
suppressed, thereby making it possible to certainly lubricate the
inside of the bearing.
[0015] Moreover, an axial end face on a side of the raceway surface
with major diameter of said outer ring member is axially closely
positioned to the side of the raceway surface with minor diameter
of said inner ring member compared with an axial end face of a side
of the raceway surface with major diameter of said inner ring
member.
[0016] In a configuration where the axial end face on the side of
the raceway surface with major diameter of the outer ring member is
axially closely positioned to the side of the raceway surface with
minor diameter of the inner ring member compared with the axial end
face of the side of the raceway surface with major diameter of said
inner ring member as described above, since a side of the ball
which fits between raceway surfaces with major diameter is widely
opened, the lubricant is discharged outside the bearing smoothly
and in a short time, so that foreign materials, such as metal
abrasion powder, are also quickly discharged with the
lubricant.
[0017] Incidentally, a line of action of a bearing portion on a
side of the raceway surface with major diameter in this ball
bearing is inclined towards a bearing portion on the side of the
raceway surface with minor diameter.
[0018] According to this configuration, even when the side of the
ball which fits between the raceway surfaces with major diameters
is widely opened, functions as the bearing, such as weight load
capacity or the like can not be deteriorated.
[0019] Moreover, a ball bearing of the present invention is a ball
bearing used in a part where a lubricant passes through an annular
space between an inner ring member and an outer ring member, it
comprises: an inner ring member having a single raceway surface; an
outer ring member which is concentrically arranged with this inner
ring member and has a raceway surface corresponding to the raceway
surface of said inner ring member; a plurality of balls arranged
between raceway surfaces of said inner ring member and said outer
ring member; and a cage for holding these balls in equally
distributed positions in the circumferential direction, wherein
said cage comprises a pocket portion for housing said balls, and an
annular portion integrally formed with this pocket portion, and
wherein said annular portion of said cage is arranged between a
shoulder portion of said inner ring member and a shoulder portion
of said outer ring member via a clearance having a radial fine
dimension.
[0020] The annular portion of the cage is arranged between the
shoulder portions of the inner and outer ring members via the
clearance having the radial fine dimension as above configuration,
so that a lubricant is supplied between the outer ring member and
the inner ring member as much amount as needed to thereby lubricate
the inside of the bearing certainly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a cross sectional view showing an entire
configuration of a differential mechanism in an embodiment of the
present invention;
[0022] FIG. 2 is an expanded cross sectional view of a principal
part in FIG. 1;
[0023] FIG. 3 is an expanded cross sectional view showing a first
double row ball bearing in FIG. 1;
[0024] FIG. 4 is a partial front view of the first double row ball
bearing in FIG. 1;
[0025] FIG. 5 is an expanded cross sectional view of a principal
part in another embodiment;
[0026] FIG. 6 is an expanded cross sectional view showing a first
double row ball bearing in FIG. 5;
[0027] FIG. 7 is an expanded cross sectional view of a first double
row ball bearing further shown in another embodiment; and
[0028] FIG. 8 is a cross sectional view showing an entire
configuration of a conventional differential mechanism.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] Hereinafter, description will be made of a ball bearing of
the present invention based on drawings taking an example of a
tandem type double row ball bearing which is applied to a bearing
for supporting a pinion shaft of a differential mechanism mounted
on a vehicle.
[0030] FIG. 1 is an entire cross sectional view showing a rough
configuration of a differential mechanism, FIG. 2 is an expanded
cross sectional view of a principal part thereof, FIG. 3 is a cross
sectional view of a first double row ball bearing where a part
shown in FIG. 2 is further expanded, and FIG. 4 is a partial front
view of the first double row ball bearing.
[0031] Description will be made of an entire configuration of a
differential mechanism 1. As shown in FIG. 1, the differential
mechanism 1 comprises a differential retaining shield 2. The
differential retaining shield 2 consists of a front case 3 and a
rear case 4. Both cases 3 and 4 are fixed by a bolt nut 2a. Annular
walls 27A and 27B for mounting bearings are formed inside the front
case 3. The differential retaining shield 2 houses a differential
transmission mechanism 5 for differentially interlocking right and
left wheels, and a pinion shaft 7 having a pinion gear 6 on one
side. The pinion gear 6 is engaged with a ring gear 8 of the
differential transmission mechanism 5. A shaft portion 9 of the
pinion shaft 7 is formed in a step shape so that the further the
other side is, the smaller the diameter thereof may become as
compared with that of one side.
[0032] The shaft portion 9 of the pinion shaft 7 is rotatably
supported by the annular wall 27A on one side (pinion side) via a
first double row angular contact ball bearing 10 (it is called a
first ball bearing). The shaft portion 9 of the pinion shaft 7 is
rotatably supported by the annular wall 27B on the other side (a
counter pinion side which is a side opposite to the pinion side)
via a second double row angular contact ball bearing 25 (it is
called a second ball bearing).
[0033] An oil circuit 40 is formed between an outer wall of the
front case 3 and the annular wall 27A on the pinion side. An oil
inlet port 41 of the oil circuit 40 is opened to the ring gear 8
side of the oil circuit 40. An oil outlet port 42 of the oil
circuit 40 is opened to a portion between the annular walls 27A and
27B. Oil 50 is stored at a level L in the differential retaining
shield 2 in a shutdown state.
[0034] As shown in FIG. 2, the first ball bearing 10 comprises a
single first outer ring member 11 having an outer ring raceway
surface with major diameter 11a on the pinion side and an outer
ring raceway surface with minor diameter 11b on the counter-pinion
side, and a first attachment 21. The first ball bearing 10 is
comprised by means of axially attaching the first attachment 21 to
the first outer ring member 11 from the pinion side toward the
counter-pinion side.
[0035] The first outer ring member 11 is fitted to an inner radius
surface of the annular wall 27A. A counter-bored outer ring is
employed as the first outer ring member 11. A plane portion 11c
which has a diameter larger than that of an outer ring raceway
surface with minor diameter 11b and extends to the outer ring
raceway surface with major diameter 11a is formed between the outer
ring raceway surface with major diameter 11a and the outer ring
raceway surface with minor diameter 11b of the first outer ring
member 11. According to the configuration described above, an inner
peripheral surface of the first outer ring member 11 is formed in a
step shape.
[0036] An annular piece 11e, which radially projects inwardly,
namely towards the first inner ring member 13 side, is integrally
formed with a shoulder portion 11h of the first outer ring member
11 on the counter-pinion side.
[0037] The first attachment 21 comprises the single first inner
ring member 13 having an inner ring raceway surface with major
diameter 13a radially opposing to the outer ring raceway surface
with major diameter 11a of the first outer ring member 11 and an
inner ring raceway surface with minor diameter 13b radially
opposing to the outer ring raceway surface with minor diameter 11b,
a set of balls 15 in a major diameter side on the pinion side and a
set of balls 16 in a minor diameter side on the counter-pinion
side, and cages 19 and 20 for holding the balls 17 and 18
comprising each set of balls 15 and 16 in equally distributed
positions in a circumferential direction. The first inner ring
member 13 is inserted in the pinion shaft 7.
[0038] An end face on the pinion side 13d in the first inner ring
member 13 contacts an end face 6a of the pinion gear 6 from an
axial direction, and the first inner ring member 13 is axially
disposed between the end face 6a of the pinion gear 6 and a plastic
spacer 23 for preload setting attached outside in the middle of the
shaft portion 9 of the pinion shaft 7.
[0039] A plane portion 13c which has a diameter larger than that of
the inner ring raceway surface with minor diameter 13b and extends
to the inner ring raceway surface with major diameter 13a is formed
between the inner ring raceway surface with major diameter 13a and
the inner ring raceway surface with minor diameter 13b of the first
inner ring member 13. According to this configuration, an outer
peripheral surface of the first inner ring member 13 is formed in a
step shape.
[0040] As shown in FIG. 3 and FIG. 4, in the first ball bearing 10,
a diameter of the ball 17 in the set of balls 15 in the major
diameter side and a diameter of the ball 18 in the set of balls 16
in the minor diameter side are equally formed, and pitch circle
diameters D1 and D2 corresponding to each set of balls 15 and 16
are different, respectively. That is, the pitch circle diameter D1
of the set of balls 15 in the major diameter side is set larger
than the pitch circle diameter D2 of the set of balls 16 in the
minor diameter side. The first ball bearing 10 which has the sets
of balls 15 and 16 whose pitch circle diameters D1 and D2 are
different like this is called the tandem type double row ball
bearing.
[0041] In the first ball bearing 10, an end face on the pinion side
11d of the first outer ring member 11, namely an axial end face on
the side of the raceway surface with major diameter is closely
located to the side of the raceway surface with minor diameter 13b
of the first inner ring member 13 (counter-pinion side) along the
axial direction as compared with the end face on the pinion side
13d of the first inner ring member 13, namely, an axial end face of
the side of the raceway surface with major diameter.
[0042] According to this configuration, the pinion side of the ball
17 in the set of balls 15 on the major diameter side is widely
opened, so that it is used as annular discharge space 60 for
discharging the oil 50.
[0043] Both lines of action 61 and 62 in the first ball bearing 10
face in the same direction. In other words, both points of
application P1 and P2 are closely located to the pinion side with
respect to an axial center of the first ball bearing 10.
Incidentally, .theta.1 represents a contact angle between a radial
plane vertical to a bearing axis C and the line of action 61 of
resultant force of forces transmitted to the ball 17 by means of
the raceway surfaces 11a and 13a of the first outer ring member 11
and the first inner ring member 13 in a bearing portion on the
pinion side (on the side of the raceway surface with major
diameter) of the first ball bearing 10. As will be obvious from
such line of action 61, even when the end face on the pinion side
11d of the outer ring member 11 is located on the side of the
raceway surface with minor diameter 13b as compared with the end
face on the pinion side 13d of the inner ring member 13, functions
as the bearing, such as weight load capacity, of the first ball
bearing 10 are not deteriorated.
[0044] The second ball bearing 25 comprises a single second outer
ring member 12 having an outer ring raceway surface with minor
diameter 12a on the pinion side and an outer ring raceway surface
with major diameter 12b on the counter-pinion side, and a second
attachment 22 as shown in FIG. 2. The second ball bearing 25 is
comprised by axially attaching the second attachment 22 to the
second outer ring member 12 from the counter-pinion side toward the
pinion side.
[0045] In the second outer ring member 12, a plane portion 12c
which has a diameter larger than that of the outer ring raceway
surface with minor diameter 12b and extends to the outer ring
raceway surface with major diameter 12a is formed between the outer
ring raceway surface with major diameter 12a and the outer ring
raceway surface with minor diameter 12b.
[0046] According to this configuration, the inner peripheral
surface of the second outer ring member 12 is formed in a step
shape. The second outer ring member 12 is fitted to an inner
peripheral surface of the annular wall 27B.
[0047] The second attachment 22 comprises a single second inner
ring member 14 having an inner ring raceway surface with minor
diameter 14a radially opposing to the outer ring raceway surface
with minor diameter 12a of the second outer ring member 12, and an
inner ring raceway surface with major diameter 14b radially
opposing to the outer ring raceway surface with major diameter 12b,
a set of balls 28 in a minor diameter side on the pinion side and a
set of balls 29 in a major diameter side on the counter-pinion
side, and cages 32 and 33 for holding the balls 30 and 31
comprising each set of balls 28 and 29 in equally distributed
positions in the circumferential direction. A stepped inner ring is
used as the second inner ring member 14. The second inner ring
member 14 is inserted in the pinion shaft 7, and the second inner
ring member 14 is axially disposed between the plastic spacer 23
for preload setting and a shield plate 37.
[0048] A plane portion 14c which has a diameter smaller than that
of the inner ring raceway surface with major diameter 14b and
extends to the inner ring raceway surface with minor diameter 14a
is formed between the inner ring raceway surface with minor
diameter 14a and the inner ring raceway surface with major diameter
14b. According to this configuration, an outer peripheral surface
of the first inner ring member 14 is formed in a step shape.
[0049] In the second ball bearing 25, a diameter of the ball 30 in
the set of balls 28 in the minor diameter side and a diameter of
the ball 31 in the set of balls 29 in the major diameter side are
equally formed, pitch circle diameters D3 and D4 corresponding to
each set of balls 28 and 29 are different, respectively. That is,
the pitch circle diameter D3 of the set of balls 28 in the major
diameter side is set smaller than the pitch circle diameter D4 of
the set of balls 29 in the minor diameter side. This second ball
bearing 25 is also the tandem type double row ball bearing.
[0050] In the second ball bearing 25, an end face on the
counter-pinion side 12d of the second outer ring member 12, namely,
an axial end face on the side of the raceway surface with major
diameter is closely located to a side of the raceway surface with
minor diameter (pinion side) of the inner ring member 22 along the
axial direction compared with an end face on the counter-pinion
side 14d of the second inner ring member 22, namely, an axial end
face on a side of the raceway surface with major diameter.
[0051] According to this configuration, the counter-pinion side of
the ball 31 in the set of balls 29 in the major diameter side is
widely opened to thereby form an annular discharge space 65 for
discharging the oil 50. Incidentally, a direction of inclination of
a line of action (not shown) in the second ball bearing 25 is a
reverse direction of inclination with respect to the lines of
action 61 and 62 in the first ball bearing 10.
[0052] Since a configuration of each of the cages 19 and 20 in the
first ball bearing 10 and a configuration of each of the cages 32
and 33 in the second ball bearing 25 have similar figures having
different diameters and axially facing to opposite directions,
description will be made of the configuration of each of the cages
19 and 20 in the first ball bearing 10 as a representative example,
hereinafter.
[0053] Incidentally, since the oil outlet port 42 of the oil
circuit 40 is opened between the annular walls 27A and 27B, it is
configured that the oil 50 used for bearing lubrication supplied
from the oil outlet port 42 of the oil circuit 40 is firstly hits
the cages 20 and 32 of an axial inside (the inside with reference
to the axial direction) among each of the cages 19 and 20 in the
first ball bearing 10 and the cages 32 and 33 in the second ball
bearing 25.
[0054] A cage so called a snap cage is used as each of the cages 19
and 20 in the first ball bearing 10, and the cages 32 and 33 in the
second ball bearing 25.
[0055] As shown in FIG. 3, the cages 19 and 20 comprises pocket
portions 19a and 20a each housing the balls 17 and 18, and annular
portions 19b and 20b integrally formed on the counter-pinion side
of these pocket portions 19a and 20a.
[0056] The counter-pinion side among the cages 19 and 20, that is,
the annular portion 20b of the cage 20 which holds the ball 18 in
the set of balls 16 in the minor diameter side is arranged between
shoulder portions 11h and 13h of the first outer ring member 11 and
the first inner ring member 13. An annular baffle piece 20c which
radially projects inwardly (on the side of the shoulder portion 13h
of the first inner ring member 13) is formed in the annular portion
20b.
[0057] A first annular clearance .delta.1 is formed between an
outer peripheral surface 20e of the annular portion 20b of the cage
20 and an inner peripheral surfaces 11f of the annular piece 11e
formed in an inner peripheral portion of the shoulder portion 11h
of the first outer ring member 11.
[0058] A second annular clearance .delta.2 is formed between an
inner peripheral surface 20f of the baffle piece 20c and an outer
peripheral surfaces 13f of the shoulder portion 13h of the first
inner ring member 13.
[0059] Radial widths d1 and d2 of the first annular clearance
.delta.1 and the second annular clearance .delta.2 are fine
clearances set to be larger than "0" and 0.15 times or less of a
diameter of the balls 17 and 18, respectively.
[0060] An end face on the counter-pinion side 11g of the first
outer ring member 11, an end face of the counter-pinion side 13e of
the first inner ring member 13, and an end face on the
counter-pinion side 20d in the annular portion 20b of the cage 20
are substantially positioned on the same radial surface,
respectively.
[0061] As described above, since the configuration of each of the
cages 19 and 20 in the first ball bearing 10 and the configuration
of the cages 32 and 33 in the second ball bearing 25 have similar
figures having different diameters and axially facing to opposite
directions, description of the cages 32 and 33 in the second ball
bearing 25 will be omitted.
[0062] As shown in FIG. 1, the differential mechanism 1 comprises a
companion flange 43. The companion flange 43 comprises a shank
portion 44 and a flange portion 45 integrally formed with the shank
portion 44. The shank portion 44 is attached outside a drive shaft
(not shown) of the shaft portion 9 of the pinion shaft 7.
[0063] Said shield plate 37 is interposed between an end face on
the pinion side of the shank portion 44 and the end face on the
counter-pinion side 14d of the second inner ring member 14. An oil
seal 46 is arranged between an outer peripheral surface of the
shank portion 44 and an inner peripheral surface of an opening on
the counter-pinion side of the front case 3. A seal protection cup
47 for covering the oil seal 46 is fixed to the opening on the
counter-pinion side of the front case 3. A threaded portion 48 is
formed in a heel on the counter-pinion side of the shaft portion 9.
The threaded portion 48 projects to a central female portion 41 of
the flange portion 45. A nut 49 is screwed on the threaded portion
48.
[0064] The nut 49 is screwed on the threaded portion 48 like this,
so that the first inner ring member 13 of the first ball bearing 10
and the second inner ring member 14 of the second ball bearing 25
are axially inserted between an end face of the pinion gear 6 and
an end face of the companion flange 43, thereby making it in a
state where a predetermined preload is given to the balls 17 and 18
of the first ball bearing 10 and the balls 30 and 31 of the second
ball bearing 25 via the shield plate 37 and the plastic spacer
23.
[0065] In the above configuration, the oil 50 is flipped up with a
rotation of the ring gear 8 in operation, is led so as to be
supplied to an upper part of the first ball bearing 10 and the
second ball bearing 25 through the oil circuit 40 within the front
case 3, and circulates through within the differential retaining
shield 2 so as to lubricate the first ball bearing 10 and second
ball bearing 25.
[0066] Incidentally, when the oil 50 is supplied into the first
ball bearing 10 as described above, the oil 50 in question flows
through an annular space A between the first outer ring member 11
and the first inner ring member 13 at high speed compared with that
of a normal double row ball bearing which is not a tandem type, so
that there is generated a phenomenon in which the oil is discharged
from an inside of the bearing in a short time. Thus, unless the oil
50 is supplied, it would be easy to fall in a poor lubricating
state in this kind of double row ball bearing. However, since it is
in a state where the oil 50 is sequentially supplied, such poor
lubricating state will not happen. Conversely, a situation of a
torque increase can be considered by the oil 50 being supplied too
much into the bearing.
[0067] However, in a case of this embodiment, the above first and
second annular clearances .delta.1 and .delta.2 are provided, and
the radial widths d1 and d2 of the first and second clearances
.delta.1 and .delta.2 are set to be larger than 0 and 0.15 times or
less of the diameter of the balls 17, respectively. Therefore, the
amount of oil 50 supplied into the annular space A is suppressed
particularly by the annular piece 11e and the baffle piece 20c.
[0068] Thus, the oil 50 will be supplied into the annular space A
as much amount as needed from the first and second annular
clearances .delta.1 and .delta.2, and the supplied oil 50 moves to
the pinion side within the annular space A. The increase in torque
is therefore suppressed, thereby making it possible to certainly
lubricate the inside of the bearing by the oil 50 as much amount as
needed.
[0069] According to the embodiment of the present invention, the
pinion side of the ball 17 in the set of balls 15 in the major
diameter side is widely opened to form the annular discharge space
60, so that the oil 50 supplied into the annular space A will be
discharged outside the first ball bearing 10 from the discharge
space 60 quickly and smoothly.
[0070] Accordingly, even when metal abrasion powder would be mixed
in the oil 5, this will be quickly discharged outside the first
ball bearing 10 from the discharge space 60 with the oil 50.
Thereby, making it possible to suppress to the minimum generation
of indentation to the inner and outer ring raceway surfaces 11a,
13a, 11b, and 13b caused by the metal abrasion powder.
[0071] In a case of the second ball bearing 25, since a flow
direction of the oil 50 only becomes an opposite direction (from
the pinion side to the counter-pinion side) to that in the case of
the first ball bearing 10, the oil 50 supplied into an annular
space B of the second ball bearing 25 certainly lubricates with the
sufficient amount of oil 50 for lubrication, and moves within the
annular space B. Accordingly, even when metal abrasion powder would
be mixed in the oil 50, the metal abrasion powder is quickly
discharged outside from the discharge space 65 with the oil 50.
Thereby, making it possible to suppress to the minimum generation
of indentation to the inner and outer ring raceway surfaces 12a,
14a, 12b, and 14b caused by the metal abrasion powder.
[0072] In this embodiment, the first ball bearing 10 with small
frictional resistance is used as the ball bearing on the pinion
gear 6 side to which a heavy load is applied compared with that on
the counter-pinion side 6. Accordingly, running torque thereof
becomes smaller compared with that of the tapered roller bearing
having been conventionally used, thereby making it possible to
improve efficiency of the differential mechanism 1. Furthermore, by
means of using not a single row ball bearing but a double row ball
bearing, it is possible to increase load carrying capacity compared
with the single row ball bearing, thereby obtaining sufficient
support rigidity.
[0073] In addition to that, there is used the tandem type first
ball bearing 10 as the first ball bearing 10, in which the pitch
circle diameter D1 of the set of balls 15 in the major diameter
side on the pinion gear 6 side is enlarged compared with the pitch
circle diameter D2 of the set of balls 16 in the minor diameter
side, so that it is possible to increase the number of balls 17 in
the set of balls 15 in the major diameter side on the pinion gear 6
side to which heavier load is applied if the balls 17 and 18 in
both rows have the same diameter, thereby making it possible to
endure the heavy load.
[0074] In each embodiment described above, shapes of both the first
outer ring member 11 and the cage 20 in the first ball bearing 10
are changed, so that it is configured so as to reduce an area of a
space formed between the shoulder portion 11d of the inner and
outer ring members 11 and 13 and an edge section of the cage 20,
but it is not limited to this.
[0075] For example, FIG. 5 and FIG. 6 are expanded sectional views
of a principal part in another embodiment of the present invention.
In this embodiment, in the first ball bearing 10 and the second
ball bearing 25 which rotatably support the pinion shaft 7 about a
shaft center, the annular portions 20b and 32b of the cages 20 and
32 of the axial inside are radially expanded inwardly and
outwardly, so that it is configured so as to reduce the area of the
space formed between shoulder portions of the inner and outer ring
members 11, 13, 12, and 14, and the annular portions 20b and 32b of
the cages 20 and 32.
[0076] When making description specifically on the side of the
first ball bearing 10, the baffle pieces 74 and 75 which radially
project inwardly and outwardly are provided in the annular portion
20b of the cage 20 on the counter-pinion side among the cages 19
and 20.
[0077] The first annular clearance .delta.1 is formed between an
outer peripheral surface 74a of the baffle piece 74 and the inner
peripheral surface 11f of the edge section of the shoulder portion
11h on the counter-pinion side of the first outer ring member 11.
The second annular clearance .delta.2 is formed between an inner
peripheral surface 75b of the baffle piece 75 of the annular
portion 20b formed in the cage 20 and the outer peripheral surfaces
13f of the shoulder portion 13h of the first inner ring member
13.
[0078] The radial widths d1 and d2 of the first and second annular
clearances .delta.1 and .delta.2 are set to be larger than 0 and
0.15 times or less of the diameter of the balls 17 and 18,
respectively.
[0079] The end face on the counter-pinion side 11g of the first
outer ring member 11, the end face on the counter-pinion side 13e
of the first inner ring member 13, and the end face on the
counter-pinion side 20d in the annular portion 20b of the cage 20
are substantially positioned on the same radial surface,
respectively. Since other configurations are similar to those of
the embodiment described above, the same symbols are given thereto
and description thereof will be omitted.
[0080] According to this configuration, the amount of oil 50
supplied into the annular space A is suppressed by the baffle
pieces 74 and 75 formed in the annular portion 20b of the cage 20,
so that the oil 50 is supplied into the annular space A from the
first and second annular clearances .delta.1 and .delta.2 as much
amount as needed. The supplied oil 50 then moves to the pinion side
within the annular space A to certainly lubricate the inside of the
bearing by the oil 50.
[0081] Moreover, even when metal abrasion powder would be mixed in
the oil 5, it is quickly discharged outside the first ball bearing
10 from the discharge space 60 with the oil 50, thereby, making it
possible to suppress to the minimum generation of indentation to
the inner and outer ring raceway surfaces 11a, 13a, 11b, and 13b
caused by the metal abrasion powder.
[0082] FIG. 7 is an expanded cross sectional view of the first ball
bearing 10 further showing another embodiment of the present
invention. In this first ball bearing 10, a machined cage is used
as the cages 19 and 20 which are formed by cutting processing,
respectively. The cages 19 and 20 comprise annular portions 70 and
71, and 72 and 73 on both sides of the axial direction of the
pockets 19a and 20a, respectively. Among the cages 19 and 20, an
axial inside in the cage 20 on the counter-pinion side, namely, the
annular portion 73 on the counter-pinion side comprises baffle
pieces 74 and 75 which radially project inwardly and outwardly, and
is formed in T section.
[0083] These baffle pieces 74 and 75 are closely positioned further
to the counter-pinion side rather than the end face on the
counter-pinion side 13e of the first inner ring member 13, and a
clearance 76 having a predetermined axial width d3 is provided
between the end face on the counter-pinion side 13e of the first
inner ring member 13 and the pinion side end face 75a of the baffle
piece 75 according to this configuration. A clearance 77 having a
predetermined radial width d4 is provided between the outer
peripheral surface 74a of the baffle piece 74 on a radial outside
and the inner peripheral surface 11f of the shoulder portion 11h on
the counter-pinion side of the first outer ring member 11.
[0084] An end face on the counter-pinion side 73a in the annular
portion 73 on the counter-pinion side of the cage 20 is positioned
on the pinion side with respect to the end faces on the
counter-pinion side 11g of the first outer ring member 11.
[0085] Thus, the first outer ring member 11 is positioned on the
counter-pinion side with respect to the first inner ring member 13,
so that the pinion side of the ball 17 in the set of balls 15 in
the major diameter side is widely opened. This opened portion is
utilized as the annular discharge space 60 for discharging the oil
50. Since other configurations are similar to those of each
embodiment described above, the same symbols are given thereto and
description thereof will be omitted.
[0086] According to the configuration described above, the pinion
shaft 7 rotates about the shaft center, the oil 50 is flipped with
a rotation of the ring gear 8, the oil 50 is led as to be supplied
to an upper part of the first and second ball bearings 10 and 25
through the oil circuit 40, and circulates within the differential
retaining shield 2 so as to lubricate the first and second ball
bearings 10 and 25.
[0087] Incidentally, an opening area on the counter-pinion side in
the annular space A between the first outer ring member 11 and the
first inner ring member 13 is reduced by the baffle pieces 74 and
75 formed in the annular portion 73 of the cage 20, so that the
clearances 76 and 77 are formed, thereby the oil 50 is supplied
into the annular space A from these clearances 76 and 77 with
limitation of its amount.
[0088] Moreover, since the pinion side of the ball 17 in the set of
balls 15 in the major diameter side is widely opened to form the
annular discharge space 60, the oil 50 supplied into the annular
space A will be discharged outside the first ball bearing 10 from
the discharge space 60 quickly and smoothly.
[0089] The oil 50 of required and sufficient amount is thus
supplied into the annular space A, and the oil 50 is subsequently
quickly discharged outside the first ball bearing 10, thereby
making it possible to suppress an increase in torque while the
first inner ring member 13 rotates about the shaft center.
[0090] Moreover, even when metal abrasion powder would be mixed in
the oil 5, this will be quickly discharged outside the first ball
bearing 10 from the discharge space 60 with the oil 50. Thereby,
making it possible to suppress to the minimum generation of
indentation to the inner and outer ring raceway surfaces 11a, 13a,
11b, and 13b caused by the metal abrasion powder.
[0091] In a case of the second ball bearing 25, since the flow
direction of the oil 50 only becomes the opposite direction to that
of the first ball bearing 10, detailed description will be
omitted.
[0092] Incidentally, in each embodiment described above, an example
in which the first and second ball bearings 10 and 25 are used for
the bearing for supporting the pinion shaft of the differential
mechanism 1 of the vehicle is shown, but it is not limited to this.
That is, it is applicable to a mechanism having a configuration
where the bearing ring which is one component of the double row
ball bearing is fixed to one side of the shaft or the housing, the
other component of the double row ball bearing is attached to the
other side of the shaft or the housing, and the shaft is inserted
into the housing.
[0093] Incidentally, in the embodiment described above, description
has been made of a case where the first and second ball bearings 10
and 25 of the tandem type have been used for an example of the
differential mechanism 1, but it is not limited to this. That is,
although not shown, if it is, for example a double row ball bearing
which is not the tandem type and has the same raceway diameter, or
a ball bearing which is a single row ball bearing and is arranged
at a part being lubricated by the oil so that the poor lubrication
is concerned, the area of the space formed between the shoulder
portion of the inner and outer ring members and the edge section of
the cage is reduced (it is made smaller in area) in the matter
similar to the above, thereby making it possible to achieve a
function effect similar to that of the embodiment described
above.
[0094] As will be obvious from the above description, according to
the present invention, it is possible to supply a lubricant with
required and sufficient amount into the ball bearing, thereby
making it possible to certainly lubricate the inside of the ball
bearing in a state of suppressing an increase in torque.
INDUSTRIAL AVAILABILITY
[0095] According to the present invention, it can be applicable to
the ball bearing used for the differential mechanism or the like
which is mounted, for example on a vehicles.
* * * * *